This invention relates to a telephone of the type that employs a card having a certain value or worth recorded thereon, and which permits a user to communicate by the telephone within the limits of the remaining value of the card.
The term "telephone" as used herein is not limited to a device for voice transmission but also covers such devices as telecopiers, also referred to as facsimile machines, terminals for data transmission and the like, which are connected by telephone or communication lines. Thus, the term "communication" as used herein includes the concept of data transmission as well as the transmission of voice signals.
Telephones which permit communication by use of a magnetic telephone card have proliferated in recent years. Rather than requiring that a user pay the telephone charge in cash each time that a communication is made, a card-operated telephone accepts payment by diminishing value data recorded on the card, which the user purchases in advance. The original value of the card is decided by the amount the user pays at the time of purchase. Thus, the telephone card is merely used as a substitute for cash payment.
A magnetic telephone card of the type described above has a magnetizable recording surface on which a large quantity of information can be stored in the form of a magnetic recording. It would be highly advantageous if such a telephone card could be provided with a large number of functions by exploiting its magnetic recording capability. So-called IC card, which comprises a microprocessor, memory, contacts for inputting or outputting data, and so on, provided within the card, also has a capability of storing a large quantity of information.